Simulating the pulse wave in the human pulmonary circulation

This thesis deals with the development and application of an existing [169] non-linear, one-dimensional mathematical and computational model of pulse wave propagation in the human pulmonary circulation with an aim to improve our ability to predict blood pressure and flow in the pulmonary arteries and veins and enhance our understanding of haemodynamic changes occurring during health and disease. The existing model by Vaughan [169] is developed in two ways, firstly by improving the descriptions of venous geometry, values of physiological parameters, inflow and outflow boundary conditions, and then by extending the model to predict pressure drop across the pulmonary vascular beds. The arteries and veins are treated as thin, homogeneous elastic tubes, and blood as a viscous, homogeneous and incompressible fluid. The non-linear effects of pulse wave propagation are predicted in the large arteries and veins, solving the governing equations by means of two-step Lax-Wendroff scheme. For an accurate haemodynamic prediction, the effects of downstream vasculature are incorporated through dynamic structured-tree matching conditions by linking the arterial and venous pressures and flows. For each blood vessel in the structured trees, linearised governing equations are solved analytically. The modelling capability is enhanced by imposing four out flow conditions at the orifices of four large veins opening in the left atrium. Considering the fundamental differences between pulmonary and systemic compliance behaviour, a revised compliance parameter value is used to obtain improved predictions of the pulmonary pressure pulse. The model is applied to various hypotheses of pulmonary hypertension to analyse the haemodynamic disorders linked with the causes of the pulmonary hypertension. The prescribed flow-rate boundary condition at the system inlet limits the occurrence of any changes in the flow patterns due to the hypertension, so a new pressure boundary condition, simulating remodelling of the heart or ventricular dysfunction, is imposed to study the effects of the hypertension on the volume flow-rate. To better understand the microcirculatory characteristic in the pulmonary circulation, under normal and diseased conditions, the model is further extended to predict the mean pressure drop across the pulmonary arterioles and venules by treating the connected structure trees not only as boundary conditions but also an active fluid dynamical part of the model. A more insightful interpretation of the results is provided by separating the pulse waveforms into incident and reflected components using Wave Intensity Analysis. Finally, the model is applied to assess the effectiveness of commonly used techniques to estimate local pulse wave velocity in the pulmonary arteries. This thesis is a step forward in understanding the performance of the pulmonary circulation and its behaviour in response to various anatomical and physiological changes in health and disease. Moreover, despite having room for further developments and validation, the model has the ability to simulate physiologically relevant pulse waveforms at a reasonable computational cost and therefore has a prospect of clinical application in the long run

Production of pectinase by Bacillus subtilis EFRL 01 in a date syrup medium

A newly isolated Bacillus subtilis EFRL 01 was used to produce pectinases in batch fermentations on various inexpensive media. A mineral medium based on waste date syrup (15 g/L) as the carbon source and yeast extract (7.5 g/L) as the nitrogen source proved to be the most effective. A 48 h batch fermentation in this medium with a starting pH of 8.0 produced a pectinase titer of ~2,700 U/mL at the optimal fermentation temperature of 45°C. The optimal temperature, initial pH, the carbon source and its concentration, and the nitrogen source and its concentration, were identified after evaluation of multiple nutrient sources and fermentation conditions.Keywords: Polygalactouronase, Bacillus subtilis, fermentation, pectinases, date syru

Analysis of Human Gait Cycle with Body Equilibrium based on leg Orientation

Gait analysis identifies the posture during movement in order to provide the correct actions for a normal gait. A person\u27s gait may differ from others and can be recognized by specific patterns. Healthy individuals exhibit normal gait patterns, while lower limb amputees exhibit abnormal gait patterns. To better understand the pitfalls of gait, it is imperative to develop systems capable of capturing the gait patterns of healthy individuals. The main objective of this research was to introduce a new concept in gait analysis by computing the static and dynamic equilibrium in a real-world environment. A relationship was also presented among the parameters stated as static \& dynamic equilibrium, speed, and body states. A sensing unit was installed on the designed metal-based leg mounting assembly on the lateral side of the leg. An algorithm was proposed based on two variables: the position of the leg in space and the angle of the knee joint measured by an IMU sensor and a rotary encoder. It was acceptable to satisfy the static conditions when the body was in a fixed position and orientation, whether lying down or standing. While walking and running, the orientation is determined by the position and knee angle variables, which fulfill the dynamic condition. High speed reveals a rapid change in orientation, while slow speed reveals a slow change in orientation. The proposed encoder-based feedback system successfully determined the flexion at 47$^\circ$, extension at 153$^\circ$, and all seven gait cycle phases were recognized within this range of motion. Body equilibrium facilitates individuals when they are at risk of falling or slipping

Production and partial characterization of invertase from Mucor geophillus EFRL 03

In the present study, cultural conditions for invertase production from Mucor geophillus using Brassica niger (oilcake) in batch wise submerged fermentation was  investigated. The effects of time period (24 to 240 h), carbon sources [Brassica campestris, B. niger, pomegranate peel, coconut, malta peel, apple pulp and glucose (control)] and nitrogen sources (peptone, yeast extract, corn steep liquor, ammonium chloride, sodium nitrates and potassium nitrate) were checked on  invertase production. The highest level of invertase was achieved using mineral medium containing 1.0% B. niger hydrolyzed with 0.3 N HCl and 0.5% yeast extract as carbon and nitrogen sources, respectively, and after 48 h of incubation at 45°C, initial pH was adjusted to 6.5. Invertase exhibited the maximum  stability in the range of 25 to 50°C temperature and 4 to 6 pH, respectively, within 10 min of incubation. The enzyme retained more than 60 and 50% activities at 8 and 70°C pH and temperature, respectively. In this study, cost effective substrate was utilized for invertase production. The pH and thermostable invertase can be  utilized in industrial process.Key words: Mucor geophillus, Brassica niger, submerged fermentation, invertase

Human Gait Recognition Subject to Different Covariate Factors in a Multi-View Environment

Human gait recognition system identifies individuals based on their biometric traits. A human’s biometric features can be grouped into physiologic or behavioral traits. Biometric traits, such as the face [1], ears [2], iris [3], finger prints, passwords, and tokens, require highly accurate recognition and a well-controlled human interaction to be effective. In contrast, behavioral traits such as voice, signature, and gait do not require any human interaction and can be collected in a hidden and non-invasive mode with a camera system at a low resolution. In comparison with other physiological traits, one of the main advantages of gait analysis is the collection of data from a certain distance. However, gait is less powerful than physiological traits, yet it still has widespread application in surveillance for unfavorable situations. From traditional algorithms to deep learning models, a gait survey provides a detailed history of gait recognition

Do mutual funds have consistency in their performance?

Using a comprehensive data set of 714 Chinese mutual funds from 2004 to 2015, the study investigates these funds’ performance persistence by using the Capital Asset Pricing model, the Fama-French three-factor model and the Carhart Four-factor model. For persistence analysis, we categorize mutual funds into eight octiles based on their one year lagged performance and then observe their performance for the subsequent 12 months. We also apply Cross-Product Ratio technique to assess the performance persistence in these Chinese funds. The study finds no significant evidence of persis- tence in the performance of the mutual funds. Winner (loser) funds do not continue to be winner (loser) funds in the subsequent time period. These findings suggest that future performance of funds cannot be predicted based on their past performance.info:eu-repo/semantics/publishedVersio

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020